Linked videos won't play

Anyone have any ideas on how to fix a problem where videos linked in emails, messages, etc. Won’t play. If I click on the play button, for a second it looks ok, then it goes back to! “Not playing” status. On one occasion, I was able to copy the link and put it in YouTube directly, and it played… Once! The rest don’t work like that. YouTube or Rumble, both. Thanks!!